The squash bug may be on its way

Jerry Vitalis

Chisago County Master Gardener

Everything has been delayed by the late spring, but vine borers, cucumber beetles and squash bugs are on their way.

Of these I find squash bugs most damaging, because they can destroy an entire crop overnight.

The squash bug will attack all members of the cucurbit family but is most common on pumpkins and squash.

It looks like a stinkbug and gives off a distinct odor when crushed. The stinkbug, however, is associated with tomatoes, soybeans and peas.

Adult squash bugs are 5/8 inch long and 1/3 inch wide. They are usually grey to black, with orange and brown stripes on the edges of the abdomen.

Adults find shelter in the fall, emerging in the spring when plants begin to grow. The females lay eggs until midsummer.

The eggs, yellow-brown to brick-red in color, are laid individually in groups of about 12 on the undersides of leaves, usually in a V-shaped pattern. They hatch in one to two weeks.

Nymphs are 3/16 to ½ inch long. They have a red head and legs with a green abdomen. As they grow, the head turns black.

Both adults and nymphs suck nutrients from leaves, disrupting the flow of water and food. Before wilting occurs, yellow specks develop. The foliage eventually turns brown. Squash bugs also feed directly on the fruit.

The adult squash bug is very difficult to kill, so early detection of nymphs is important.

If only a few plants are affected, destroy the bugs and eggs. Spray as the eggs are hatching and throughout the season, using a proper insecticide recommended in the Midwest Vegetable Production Guide (BU-7094-S).